1. Field of the Invention
The present invention relates in general to an engine, and in particular to a component layout for a marine engine, including an arrangement of fuel injectors within the engine.
2. Description of the Related Art
Internal combustion engines are commonly used to power small watercraft such as personal watercraft. These watercraft include a hull which defines an engine compartment. The engine is positioned in the engine compartment. The output shaft of the engine is coupled to a water propulsion device to propel the watercraft.
Air must be supplied to the engine from outside the hull for use in the combustion process. Typically, air flows through one or more ducts in the hull into the engine compartment, and then through an intake system of the engine to the combustion chamber(s) of the engine.
Fuel also is supplied to the engine for use in the combustion process. In order to accurately meter the fuel, to improve engine operating efficiency and performance, and to better control emissions, many personal watercraft manufacturers are employing fuel injections system in which one or more fuel injectors inject fuel into the engine. In such systems, fuel is supplied to the fuel injectors at high pressure. Each injector has an electrically operated valve which selectively opens and closes, controlling the flow of fuel through the injectors to the engine.
Such systems, however, are not easily employed in a manner ensuring the system's durability on such watercrafts. Personal watercraft are sporting in nature; they turn swiftly, are easily maneuverable, and accelerate quickly. As a result of their sporting nature, they may at times become inverted or at least partially capsized While personal watercraft are designed to float under such conditions (and are easily righted), some water commonly enters the engine compartment under all conditions, even when upright through the air ducts. Such water can damage sensitive components of the fuel injection system, such as, for example, the fuel injectors. This problem is exacerbated should such components become submerged before the watercraft is righted.